Abstract: A pressure relief panel assembly for rupture discs, explosion vents and the like has a plurality of frangible panel portions which burst at different pressures to present a pressure relieving aperture having a cross-sectional area which varies in accordance with the number of panel portions which have ruptured. In one embodiment of the invention, the assembly comprises two frangible panels positioned in face-to-face relationship in covering disposition to a vent opening, and the innermost panel has an orifice which functions as a pressure relieving aperture once the outermost panel ruptures; subsequently, further build up of pressure causes the innermost panel to burst and present a pressure relieving aperture larger than the orifice so that the structure to be protected is fully vented. In certain forms of the invention, a discontinuous pattern of perforated lines of weakness in the innermost panel serve as pressure relieving apertures once the outermost panel ruptures.

Abstract: A missile bulkhead rupture disc assembly for disposition between adjacent solid propellant stages which are ignited in sequential order has a central aperture which receives an igniter for detonating the first stage of propellant. In preferred forms, the rupture disc comprises a pre-bulged frangible element having a first burst pattern with a circular line of weakness circumscribing a central portion of the element surrounding the igniter, and the element also has a second burst pattern comprising a plurality of lines of weakness which extend in a radial direction outwardly from the circular line of weakness of the first burst pattern, and which are spaced from each other to define generally sector-shaped petals or segments of the frangible element.

Abstract: Micro-scale chemical process simulation apparatus is disclosed which is useful for design of full-scale processes and associated equipment as well as emergency relief systems. A thin-walled vessel for receiving a quantity of the material to be evaluated is supportd within and thermally insulated from the walls of a surrounding containment unit. A guard heater is provided around the vessel and temperature thermocouples and pressure transducers are strategically located to monitor the temperature conditions existing in the material in the vessel as well as the pressure within the vessel and the containment unit respectively. Fluid may be selectively introduced into or exhausted from the containment unit to maintain a required pressure balance between the interior of the vessel and that of the containment unit.

Abstract: A burst panel assembly for normally covering a vent opening of structure which defines an area to be protected from the buildup of dangerously high internal pressures has two frangible panels disposed in spaced, face-to-face relationship along with a core of expanded polyurethane foam which functions to dampen vibrations received from the structure and transmitted to the frangible panels. The foam is introduced in an initially flowable condition into the space between the panels and thereafter expands while curing to a solidified configuration for continuously exerting pressure on both of the panels, to thereby substantially reduce the fatigue stress that would otherwise occur along lines of weakness of burst patterns that are formed in both of the panels.